Hollow brick mold box

ABSTRACT

Hollow bricks are molded about cores supported by core bars in a mold box. The moldable material in the box is compacted by a pair of vertically movable compaction tools. The core bars are of beveled cross section to form respective vertically extending camming surfaces tapering upwardly and downwardly, and each core bar is centered between the compaction tools of each pair of tools, with one of the camming surfaces facing a respective tool during vertical movement of the tools adjacent the bar. Springs normally reciprocate the tools of each pair towards each other, the camming surfaces being arranged first to reciprocate the tools apart as the tools vertically move downwardly into contact with the camming surfaces and, upon further downward movement, to permit reciprocation towards each other by the action of the springs.

i. Unite States atent 1151 3,655,322 Kaitna [4 Apr. 11, 1972 [541 HOLLOWBRICK MOLD BOX 3,187,393 6/1965 Harris ..25/41 T x [72] Inventor: WalterKaima, Vienna, Austria 2,492,415 12/1949 Coates et a1 ..25/41 T [73]Assignee: Wienerberger Ziegeliabriks-Und Bau- Primary ExaminerRobert D.Baldwin gesellschaft Assistant Examiner-Ben D. Tobor 22 Filed: Feb. 24,1970 21] Appl. No.: 13,665 1 1 ABSTRACT Hollow bricks are molded aboutcores supported by core bars [30] Foreign Application Priority Data in amold box. The moldable material in the box is compacted by a pair ofvertically movable compaction tools. The core Feb. 25, 1969 Austria ..A1909/69 bars are of beveled Cross Section to form respective verticallyextending camming surfaces tapering upwardly and [22] 9.8.51 downwardly,and each core bar is centered between the q 25/41 T paction tools ofeach pair of tools, with one of the Camming 1e 0 earc surfaces facing arespective too] during vertical movement of the tools adjacent the bar.Springs normally reciprocate the [56] References cued tools of each pairtowards each other, the camming surfaces UNITED STATES PATENTS beingarranged first to reciprocate the tools apart as the tools verticallymove downwardly into contact w1th the cammlng 2,932,876 4/1960 Zevely..25/41 T Surfaces and, upon f h downward movement to permit 1167113255/ 1 928 Straub T X reciprocation towards each other by the action ofthe springs. 2,319,291 5/1943 Besser ...25/41 T X 2,160,462 5/1939Schieferstein 25/41 T X 5 Claims, 6 Drawing Figures PATENTEDAPR 1 1 I972SHEET 2 [IF 2 HOLLOW BRICK MOLD BOX The present invention relates to ahollow brick molding machine of the type including a mold box containingcores supported by core bars extending across the top of the mold box.The mold box is formed by front, rear and end liners, the mold boxliners and the cores defining a molding chamber whereinto moldablematerial may be poured for molding hollow bricks about the cores. A pairof vertically movable compaction tools are mounted for compactingsurface areas of the moldable material in the mold box upon verticalmovement of the compaction tools into engagement with the surface areas.

In conventional mold boxes of this type, the compaction tools adjacentthe core bars had to be spaced a certain distance from each other topermit them to bypass the bars during the vertical movement of thetools. Although the bars could be made of relatively narrow crosssection to reduce the space between the compaction tools, some spaceinevitably remained between the tools leaving a gap where no compactionwas effected. Thus, the surface zone of the molded brick below the corebars was insufi'rciently compacted, causing cracks to occur even duringstorage or curing and thus adversely affecting the quality and strengthof the molded bricks.

It is the primary object of the invention to eliminate this deficiencyand to provide a mold box for molding hollow bricks of high quality anduniform stability wherein all surface areas, including those underneaththe core bars are uniformly compacted.

This object is accomplished in accordance with the present inventionwith core bars of beveled cross section to form respective verticallyextending camming surfaces. Each core bar is centered between thecompaction tools of each pair of tools, with one of the camming surfacesfacing a respective one of the compaction tools during vertical movementof the tools adjacent the bar. Biasing means normally reciprocate thecompaction tools of each pair towards each other, the camming surfacesbeing arranged first to reciprocate the tools apart as the toolsvertically move downwardly into contact with the camming surfaces and,upon further downward movement, to permit reciprocation towards eachother by the action of the biasing means.

The above and other features of the invention will be better understoodby reference to the attached drawing showing certain embodiments of theinvention, and wherein FIG. I shows a side view of the compaction tools,with portions of the tool support and mold box in cross section;

FIG. 2 is a partial end view of FIG. 1 in the direction of arrow II;

FIGS. 3 and 4 are detailed views showing modified shapes of thecompaction tools;

FIG. 5 illustrates successive stages in the downward movement ofthecompaction tools ofFIG. l; and

FIG. 6 is a top view of a mold box comprising several mold compartments.

Referring now to the drawing, the mold box is shown to comprise frontand rear liners l, 1 and end liners 2, 2, a plurality of mold cores 3being positioned in the box to form cavities in the bricks to be moldedin the box. As shown in FIG. 6, a pair of rails 4, 4 are affixed to thetop edge of rear and front liners 1 of the box, and a feed pan (notshown) may be moved along the rails to supply moldable material throughthe open top of the mold box, a series of such mold boxes being placedside-by-side along the rails, if desired.

As also shown in FIG. 6, lugs 5 projecting from the support framework ofthe mold box enable the entire apparatus to be gripped and lifted fortransport to different locations.

Furthermore, it will be seen from this figure that hollow bricks ofdifferent shapes may be molded in the mold box, bricks A being ofrectangular-cross section while brick B has a front extension for makingwall portion adjacent to doors or windows, for instance. For thispurpose, special dividing plates 6 and 6 are inserted in the mold box,according to the desired shapes ofthe bricks to be molded.

The mold cores 3 are secured by conventional means, not shown forclaritys sake, to core bars 7 extending across the top of the mold boxparallel to liners 1, 1 approximately centrally of the respective coresand the end faces 8 of the hollow bricks, the rear and front faces 9 ofeach brick defining a cavity therein with its end faces.

A pair of compaction tools 10, 11 is mounted laterally adjacent eachcore bar 7, which tools are vertically adjustable and may also bevibratory, as is well known, for application to the surface of themoldable material in the mold box, the tools being positioned betweencores 3 and the mold box liners 1 and 2. In this manner, tools 10 willcompact the front and rear walls 9 of the bricks (see FIG. 1) whiletools 11 will compact the end walls 8 thereof.

The compaction tools 11 are shaped partially to conform to thoseportions of compaction tools 10 facing them so that the conformingportions of the tools cooperate to engage substantially the entiresurface of brick end walls 8. Furthermore, the tools' 11 are shaped tomold the desired surface configuration of brick walls 8. Thus, tools 11are shaped to produce a recess of trapezoidal cross section in brickwall 8, as seen in FIG. 1. In the modification of FIG. 3, the tools 11are shaped to mold a stepped recess having a bottom of arcuate crosssection in the surface of the brick wall 8'. The tools 11" of FIG. 4mold a flat, shallow depression into the surface of the brick wall 8".It will thus be obvious that any desired surface configuration may beimparted to the brick walls by correspondingly shaping the compactiontools.

The compaction tools 11, 11, 11" are secured to the ends of plungers 12'while compaction tools 10 are secured to the ends of plungers 12, theplungers being suspended from vertically movable carrier plate 13. Theupper ends 14 of the plungers are passed through corresponding bores inthe carrier plate and are threadedly secured by nuts 15, 15' on theplate.

While plungers 12 are rigid, each plunger 12 is articulated about pivotpin 16 for pivotal movement of the compaction tool secured thereto inthe direction of front and rear walls 9 of the hollow brick, i.e., in afore-and-aft direction in respect of the mold box. In the illustratedembodiment, split rings 16 hold the pivot assembly in place.

A pair of stops l7, l7 limit the pivotal movement of the plungers 12,compression springs 18 being mounted normally to bias the plungers 12',12' against each other so that the compaction tools 11, 11', 11" faceeach other adjacent the core bar 7.

Spring 18 is mounted between plunger 12 and an abutment plate 19, thespring being coiled about bolt 19 passing through the abutment plate. Anut 18' threadedly engages the outer end of the bolt so that movement ofthe nut 18' in relation to the bolt 19 adjusts the bias of spring 18.

FIG. 5 illustrates the successive stages of the operation of thecompaction tools during the vertical movement thereof. As shown, thecore bar 7 is of beveled cross section, forming respective cammingsurfaces projecting ledges of the compaction tools. Thus, as the toolsdescend the camming surfaces of the core bar will first move the toolsapart and, as the tools continue to slide over the camming surfaces ofbar 7, they will automatically pennit them to move together again underthe bias of spring 18.

While the invention has been described and illustrated in connectionwith certain preferred embodiments, variations and modifications thereofwill readily occur to those skilled in the art without departing fromthe scope of this invention, as defined in the appended claims.

I claim:

1. In a hollow brick molding machine of the type including a mold boxcontaining cores supported by core bars extending across the top of themold box, the mold box being formed by from, rear, and end liners, themold box liners and the cores defining a molding chamber whereintomoldable material may be poured for molding hollow bricks, and a pair ofvertically movably compaction tools for compacting surface areas of themoldable material in the mold box upon vertical movement of thecompaction tools into engagement with said surface areas,

wherein the improvement comprises was inserted:

l. the core bars being of beveled cross section to form respectivevertically extending camming surfaces taperin g upwardly and downwardly,

2. each core bar being centered between the compaction tools of eachpair of tools, with one of the camming surfaces facing a respective oneof the compaction tools during vertical movement of the tools adjacentthe bar, and,

3. biasing means for normally, biasing the compaction tools of each pairtowards each other,

a. the camming surfaces being arranged first to reciprocate the toolsapart as the tools vertically move downwardly into contact with thecamming surfaces and, upon further downward movement, to permitreciprocation towards each other by the action of the biasing means.

2. In the hollow brick molding machine of claim 1, the compaction toolshaving beveled ledges for contact with the camming surfaces.

3. In the hollow brick molding machine of claim 1, means for pivotallymounting the compaction tools about a pivoting axis extending in thedirection of the core bar with which the tools are associated.

4. In the hollow brick molding machine of claim 1, further comprising anadditional pair of vertically movable compaction tools, the additionalcompaction tools being held rigid in respect of the reciprocablecompaction tools, and one of each of the rigid compaction toolscooperating with a respective one of the reciprocable compaction toolsfor compacting substantially the entire surface area of the moldablematerial in the mold box.

5. in the hollow brick molding machine of claim 4, each rigid compactiontool overlapping the cooperating reciprocal compaction tool, thereciprocal compaction tool being recessed to receive the overlappingportion of the rigid compaction tool.

1. In a hollow brick molding machine of the type including a mold boxcontaining cores supported by core bars extending across the top of themold box, the mold box being formed by front, rear, and end liners, themold box liners and the cores defining a molding chamber whereintomoldable material may be poured for molding hollow bricks, and a pair ofvertically movably compaction tools for compacting surface areas of themoldable material in the mold box upon vertical movement of thecompaction tools into engagement with said surface areas, wherein theimprovement comprises was inserted:
 1. the core bars being of beveledcross section to form respective vertically extending camming surfacestapering upwardly and downwardly,
 2. each core bar being centeredbetween the compaction tools of each pair of tools, with one of thecamming surfaces facing a respective one of the compaction tools duringvertical movement of the tools adjacent the bar, and,
 3. biasing meansfor normally, biasing the compaction tools of each pair towards eachother, a. the camming surfaces being arranged first to reciprocate thetools apart as the tools vertically move downwardly into contact withthe camming surfaces and, upon further downward movement, to permitreciprocation towards each other by the action of the biasing means. 2.each core bar being centered between the compaction tools of each pairof tools, with one of the camming surfaces facing a respective one ofthe compaction tools during vertical movement of the tools adjacent thebar, and,
 2. In the hollow brick molding machine of claim 1, thecompaction tools having beveled ledges for contact with the cammingsurfaces.
 3. In the hollow brick molding machine of claim 1, means forpivotally mounting the compaction tools about a pivoting axis extendingin the direction of the core bar with which the tools are associated. 3.biasing means for normally, biasing the compaction tools of each pairtowards each other, a. the camming surfaces being arranged first toreciprocate the tools apart as the tools vertically move downwardly intocontact with the camming surfaces and, upon further downward movement,to permit reciprocation towards each other by the action of the biasingmeans.
 4. In the hollow brick molding machine of claim 1, furthercomprising an additional pair of vertically movable compaction tools,the additional compaction tools being held rigid in respect of thereciprocable compaction tools, and one of each of the rigid compactiontools cooperating with a respective one of the reciprocable compactiontools for compacting substantially the entire surface area of themoldable material in the mold box.
 5. In the hollow brick moldingmachine of claim 4, each rigid compaction tool overlapping thecooperating reciprocal compaction tool, the reciprocal compaction toolbeing recessed to receive the overlapping portion of the rigidcompaction tool.